In rural areas, it is common for mailboxes to be mounted on posts at the roadside. In many instances, a mail box may be damaged or broken off due to impact from the snow from the snowplow, and other foreign objects such as ice, dirt, stone, etc. Once a mailbox is broken off, it is often difficult and quite annoying to replace it. Because most mailboxes are mounted on support posts that are, in turn, mounted in concrete, once a mailbox is broken, part of the support post remains in the ground firmly embedded in the concrete. This creates a problem for any replacement mailbox. The concrete block must be removed and replaced or the new mailbox must be located at a location that is spaced apart from the old mailbox. Neither of these solutions is entirely satisfactory. Therefore, there is a need for a mailbox that can be easily replaced if damaged, yet will be securely anchored when it is in place.